等离子体技术沉积SiCN薄膜中杂质O的来源、化合状态及其对薄膜结构和性能的影响

Characterization of Oxygen Impurities in SiCN Films

利用微波ECR等离子体增强非平衡磁控溅射法制备了硅碳氮(SiCN)薄膜,并利用X射线光电子能谱、扫描电镜、椭偏光谱仪等对薄膜成分、结构、性能等进行表征。结果表明薄膜中O杂质含量及其结合态对薄膜的化学结构和机械性能都产生了很大影响。Si靶溅射功率最低时(100W),薄膜中O杂质含量高达10.63%,以Si-O键结构为主,此时薄膜的疏松结构导致大气环境下O的化学吸附是O杂质的主要来源;在高Si靶溅射功率情况下(>250W),薄膜中O杂质含量低于4%,且以C-O键结构为主,薄膜致密,硬度最高达29.1GPa、折射率可达2.43。

The SiCN films were deposited by microwave cyclotron resonance （ECR） plasma enhanced unbalance magnetron sputtering on Si substrates. The microstructures and properties of the films were characterized with X-ray photoelectron spectroscopy （XPS）, scanning electron microscopy （SEM） and ellipsometry spectroscopy. The results show that the RF sputtering power of Si target determines the O impurity density, and that the O density and its chemical bonding mode strongly affect the stoichiomctries, microstructures and mechanical properties of the films. At the lowest power of 100W, the maximum O density was found to be 10.63 % and Si-C bonds dominated, possibly because of the chemical adsorption of the loose structures of the films. At a high sputtering power, high than 250W, the O density was lower than 4%, and C-O bonds were predominant and fairly compact SiCN films, with a hardness of 29.1GPa and a reflective index of 2.43, were grown.